


On The Edge

by outoftheashes



Category: Supernatural
Genre: Bottom Castiel, Community: spn_kinkmeme, Dubious Consent, Established Castiel/Dean Winchester, First Time, Fondling, Frottage, Multi, Prompt Fill, Sloppy Seconds, Voyeur Dean, Voyeurism
Language: English
Status: Completed
Published: 2016-11-02
Updated: 2016-11-02
Packaged: 2018-08-28 15:14:29
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,925
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/8451364
Author URL: https://archiveofourown.org/users/outoftheashes/pseuds/outoftheashes
Summary: Cas is Dean's boyfriend, but it doesn't stop Sam from coming on to him.





	

**Author's Note:**

> I'm new to writing Destiel, so please be gentle with me. I also don't tend to write top Dean, so. It was a challenge. 
> 
> This was written for a spn kink meme prompt that I didn't fully adhere to. If there's tags I somehow missed let me know and I'll add them - but I think I added the most important bits. 
> 
> WARNING: Cas says no multiple times throughout this fic to Sam's advances (although he enjoys what Sam does to him), so if that triggers you, please turn back now.

The frequency of Sam’s touches have increased dramatically, but it’s no cause for concern. _He’s harmless._

They’re easy touches. Comfortable.  

Until they’re not.

“You look good, Cas,” Sam says and the way he _stares_ at him has his pulse quickening. He knows what it means because his boyfriend Dean looks at him the same way.

“Thank you,” he replies stiffly, putting space between them.

Sam’s grin is predatory. He gestures at himself, still eyeing Cas in a way that is leaving him feeling exposed. Sam’s wearing a white dress shirt and form fitting pants that Castiel has been carefully ignoring.

“What, you don’t think I look good, too?”

Good? Good is not the word Castiel would use.

“You look fine.” He takes another step away from his friend. “I must go. Enjoy your date with Eileen.”

“I’d enjoy it more if you were coming with me,” Sam calls after him.

 

* * *

 

“Wanna fuck you so bad,” Sam breathes in Cas’ ear, cupping his cock for the briefest of moments before his hands roam to his hips, his ass.

“Sam,” he grits out, putting down his coffee cup and clutches the countertop in the kitchen. “No. It’s wrong. I’m with your brother so you need to stop.”

Sam doesn’t listen. He presses Castiel even more firmly against the counter, a hand on the base of his skull so his face is resting on it too, and rolls his hips teasingly so Cas can feel the entire length of his dick.

It’s a considerable size.

Father help him, he’s aroused. A part of him wants Sam, a much bigger part than what should be there. It’s obvious by the mess he’s making in his pants.

“Come on,” Sam says in a tone that is probably meant to sound sweet but is anything but. “Just a little longer so I have something to think about when I jack off later.”

“I said _no_ ,” he growls, but his dick has completely betrayed him and his interest. “Your brother will be up any minute. He’ll see -”

“We both know that’s a lie.”

It is. Dean’s exhausted from killing a nest of vampires mere hours earlier.

“He’ll be angry,” He pauses, breathing deeply. “Why aren’t _you_ resting?”

“I’ve got better things to do.”

“Sam, this is highly inappropriate.”

“Can you tell me you hate it?” He runs his tongue along the nape Cas’ neck, making him shiver. “Because I don’t think you can.”

It’s true - he can’t.

“I’m telling you _no._ That should be enough, Sam. This isn’t like you.”

“That’s what you think, huh?”

There’s a sound of a zipper being pulled downward and Sam grunts quietly. Castiel can only assume he’s taking his cock out, especially when he tugs Cas’ pants down so the only physical barrier he has left is his underwear. “You’re gonna like this, Cas -”

“Sam, you can’t -”

“Oh, yes I _can.”_

Sam presses his bare cock against Cas’ ass. If his underwear weren’t in the way that delicious cock would be easily sliding between his cheeks. He rolls his hips slow and dirty, grinding on him.

“By the time I’m finished you’re gonna be _begging_ me to fuck you. You’ll want this again -”

“I don’t want a repeat,” he lies. “I don’t want this at all.”

“You can’t lie for shit.” Sam’s breath ghosts along Cas’ skin as he pleasures himself. “I can’t fucking wait for you to come on my dick.”

“That would be rape.”

“No, it wouldn’t.”

Sam comes all over Cas and immediately begins rubbing what little that he can into the angel’s skin, marking him.

“What are you -”

“Shh. I’ve got you.”

Sam slips a hand into his underwear and strokes two fingers over his hole. Castiel comes as soon as those thick fingers begin to penetrate him, cursing Sam the whole time.

 

* * *

 

Castiel heals his body after every encounter with Sam. The younger Winchester can’t go more than a week without cornering and touching him and he’s not at all picky about where it occurs. Various surfaces have been used, but walls are Sam’s favorite.

He’s not overly rough with Cas, but he enjoys marking him with hickeys and come stains. It’s not something he’s prepared for Dean to see after months of continuously hiding the evidence.

He almost wants Dean to catch Sam in the act. He wants Dean to tell Sam to stay away...

So why does he keep imagining Sam’s thick cock fucking him wide open every time he feels his arousal?

 

* * *

 

Nothing he says phases Sam. Nothing makes him back off. He’s an Angel of the Lord, but Sam Winchester isn’t afraid of him.

After four months of being cornered, of Sam trying to touch him more and more intimately, Sam comes to him while he’s in the shower. He’s not sure why he thought it would be safe here -

_If you really wanted to get away you could leave._

Sam wastes no time getting right into Castiel’s space. The angel can feel every hard, wet inch of him.

“Sam,” Castiel pants, squirming as those big hands explore his stomach and slowly drift down to his cock. “Why won’t you listen?”

“You could fight me off,” Sam points out, brushing his fingertips along the head of Cas’ dick. “You could _make me_ stop _,_ but you haven’t and both of us know why.”

“I don’t want to hurt you,” Castiel says.

Sam ignores him and spreads Cas’ ass cheeks so his cock rests snugly against his hole. “This is _mine._ Don’t you wanna be mine? Don’t you want _all_ of me? Can fill you up, give it to you rough, give you what you’re missing.”

“I love Dean. There is nothing to miss.” It’s true. There’s no doubt in his mind that it’s true, but it’s not stopping him from being hot all over and it’s not from the spray of water.

It doesn’t stop him from being on the edge of saying _yes._

 

* * *

 

After Sam leaves him to finish up his shower alone he realizes it’s time, it’s now or never - Dean must know what Sam’s done, what Cas has failed in stopping…

Even if it means that what he has with Dean ends.

Dean’s happily eating a slice of cherry pie in the kitchen, not even bothering to sit down because he’s inhaling it. The moans he makes are incredibly similar to how he sounds when he fucks Cas.

“I need to speak with you.”

“Go for it,” Dean says, wiggling his brows. “Is it about dinner? Because I’ve already got some fuckin’ awesome ideas -”

His stance is rigid and he does his best to search for the proper words - this has never been a skill of his. “No. It’s not about dinner. It’s about Sam.”

Dean puts his pie on the counter and gives Castiel his full attention. Perhaps the tone of Cas’ voice alerted him that something is wrong. “Yeah? What’s up with Sammy?”

Cas has been ready to kill or die for the Winchesters’ at every turn. He can do this too - even if it breaks Dean’s heart, his trust.

“Sam wants to fuck me. He’s been… increasingly difficult over the last few months. At first, it was just friendly touches, but it has escalated quite severely and he -” he pauses. “Just now, in the shower, I almost gave in. He… he came in, touched me everywhere and came on me. It’s not the first time he’s had an orgasm while touching me. Dean, I’m so _sorry_ -”

“Hey, hey.” Dean pulls Cas into a hungry kiss and it’s all teeth, tongue, and _passion._ “You can fuck him if you wanna.”

“I- what? Dean… why?”

He was expecting anger. He was expecting jealousy. He was expecting Dean to tell him or Sam to leave the bunker.

_Not this._

“Because I love the idea of sharing my boyfriend with my brother. We share everything else,” he said, flicking his tongue out between his teeth. “If you say yes you better let me fuck your used hole after he’s had a go.”

The words tumble out automatically. “I’m interested.”

“Mm. Fuck yeah. Let’s go tell Sammy then, yeah?”

 

* * *

 

As soon as they inform Sam of their decision the younger Winchester is touching Cas in a near feral manner and pulling him away to his room as if he hadn’t just come an hour prior.

Cas takes advantage of his powers and makes their clothes disappear with a single thought.

“Nice… think I would have preferred taking the clothes off you myself, though,” Sam murmurs then tackles Cas onto the bed, on his back so he’s staring up at him.

“Perhaps if there is a next time -”

“There will be.”

Cas rolls his eyes.

“Your ego is not endearing.”

Sam pushes Cas’ legs up to his chest so he can get a look at his hole and hisses when his fingers slip inside Cas’ asshole without issue. “What -”

“My grace,” Cas says, then pulls Sam closer to him with his legs. “I prepped myself with it.”

“F-fuck…” Sam breathes, watching as his cock enters Cas and touches the place where they’re joined.

“I thought you were going to be rough.”

Sam tears his gaze off of Cas’ ass.

“You sure?”

Castel quirks a brow. “Don’t ask stupid questions.”

Sam barks out a laugh and grabs Cas’ hips, shoving into him hard and desperate, making Cas gasp every time that sweet cock grazes his prostate.

“Dean’s watching,” he says with difficulty. “Right outside the door. His thoughts are so loud it’s impossible not to hear.”

“Please don’t talk about my brother while I’m fucking you.”

“He wants to use me when you’re done.”

“Cas, I’m not kidding -”

Cas clenches hard around Sam, making him groan low. “You’re going to come soon. Aren’t you, Sam?”

“You’re coming first.”

The angel meets him thrust for thrust, moaning as Sam takes him higher. After all the months of resistance finally giving in feels so _good._

He’s been expecting it to feel wrong and it’s not.

In the end, Sam is right - he comes first. That thick cock hitting his prostate without mercy is partly the cause, but so is the noises Sam keeps making. He sounds undone.

Cas likes it too much.

Sam comes not long after Cas, sucking an ugly hickey into his throat.

It’s then that the bed dips as Dean joins them on top of it.

Sam hazards a glance at his brother and snorts when he sees that he’s already naked. “Jesus, Cas wasn’t kidding. Alright, alright. I’m done…”

The younger Winchester pulls out of the angel and Dean whines, eyes locked on Cas’ hole. “Fucking hot.”

Dean dips his finger inside Castiel’s fucked out asshole and the angel tilts his hips, eager for more. “No teasing, Dean. Not right now.”

“Are you fucking kidding me? I’m savoring this. You’re so fucking sloppy. So pretty all full of come…”

“You are acting as though you’ve never seen me like this before, Dean.”

“Not with another man’s come dripping out of you, I haven’t.”

Cas and Sam groan at the same time and the younger Winchester looks wrecked. Dean’s careful to keep his eyes off of his brother and Castiel assumes it’s because he would find it awkward.

“I wanna see how many loads we can give him today. You interested?” Sam asks, making himself comfortable next to Cas.

Dean trembles as he lines up, pushes into Castiel and bottoms out. “Like the way you think, Sammy.”

“So do I,” Cas adds, reaching out and squeezes Sam’s hand.

 

**Author's Note:**

> Full prompt: 
> 
> Cas is Dean's boyfriend, but that doesn't stop Sam from coming onto him. 
> 
> It starts with casual touches, compliments and invitations at first, but soon progresses from there, with Sam cupping and caressing Cas through his clothes and whispering into his ear how badly he wants to fuck him. 
> 
> Cas is extremely turned on by it, but feels that it would be wrong to cheat on Dean, so he keeps telling Sam no. But since he doesn't actually fight him off or even just leave, and is very obviously aroused, Sam keeps cornering him and coaxing him into letting himself be touched more and more intimately. 
> 
> I'd love to see Sam bending Cas over and rubbing his erection between Cas's asscheeks through clothes or underwear, for example, or Sam sticking his hand down Cas's trousers and fingering his hole while he rubs his own dick against Cas's hip, talking dirty all the time. 
> 
> At some point, Sam comes in while Cas is in the shower, presses their wet, naked bodies together and touches a squirming Cas everywhere. It turns Cas on so much, he almost gives in and lets Sam fuck him right there. 
> 
> Afterwards, he is appalled at himself, and confesses the whole thing to Dean (after trying desperately to hide everything (hickies, come stains, etc) from him for months). 
> 
> Except, instead of angry or jealous, Dean is delighted by the idea of sharing his boyfriend with his brother and fucking his sloppy hole after Sam has had a go.


End file.
